摘要:The resonant periodic gain (RPG) active region with different Al composition in AlxGa1-xAs spacer layers was designed using PICS 3D simulation software to investigate the photoelectric characteristics of a 940 nm vertical cavity surface emitting laser (VCSEL), aiming to achieve high output power and high power conversion efficiency. Simulation results indicate that the peak output power of the RPG VCSEL reaches 24.32 mW, and the peak power conversion efficiency reaches 51.7% when the Al composition of the spacer layer is 0.1. The transport properties of carriers in the active region of the RPG VCSELs were investigated through analysis of the band structure of the spacer layer. The results show that adjusting the Al composition can regulate its band structure and control the radiation recombination probability. This effectively reduces the accumulation of electron and hole in the spacer layer, thereby reducing non-radiative recombination. This study provides theoretical guidance and data support for selecting spacer layer materials in strain compensated quantum well RPG active regions.
关键词:vertical cavity surface emitting laser;high output power;resonant periodic gain active regions;AlxGa1-xAs spacer layer
REN Wei-jie, LIU Zi-jiang, WANG Qing-kai, XU Wen-jun, QIN Zhen-xing
DOI:10.37188/CJL.20250157
摘要:Shape memory materials, as a type of intelligent materials that can restore to their initial state under external stimuli, have shown great potential in emerging fields such as flexible electronics, smart packaging, and biomedicine. However, the shape recovery efficiency of traditional polyvinyl alcohol (PVA) materials in water is greatly limited. Here reports a novel photo-responsive shape memory material based on a PVA/Carbon dots composite, which exhibits superior shape recovery performance in water compared to pure PVA by combining the Carbon dots with PVA. The results obtained here have shown that the hydrogen bonds formed between the Carbon dots and PVA are an important factor in enhancing the shape memory effect. The introduction of silicon elements into the Carbon dots significantly improves the shape recovery speed in the composite, which is about three times higher than that of pure PVA. This is due to the silicon-doping of the Carbon dots significantly enhance the photothermal conversion efficiency of the composite material to result in converting more solar energy into heat under sunlight conditions, thereby, accelerating the movement of molecular chains and achieving rapid shape recovery. Considering that as-prepared composite has the excellent controllable deformation performance and water-responsive characteristics, which provides a new idea for the development of efficient light-thermal-water multi-responsive intelligent materials.
WANG Xin, SUN Xianze, CHENG Kang, ZHAO Haiyan, TIAN Ke, LU Zhizhong, WANG Shunbin, JIA Shijie, WANG Pengfei
DOI:10.37188/CJL.20250152
摘要:In this paper, a microscale near-infrared microsphere laser was demonstrated, based on a phase-separated glass matrix doped with Ho3+ ions. The glass microsphere with a diameter of 42.81 μm was fabricated, exhibiting a high optical quality factor (Q) of 1.25 × 106 and a high damage threshold. Pump light was coupled into the microsphere using a tapered optical fiber, resulting in efficient excitation of the rare-earth ions, and single-mode laser emission at 2.04 μm was observed from the microspherical resonator. Additionally, the glass transition temperature (Tg) was employed as an indicator of the device’s resistance to laser-induced damage, confirming that stable operation can be achieved under complex environmental conditions.
摘要:Gallium oxide (Ga2O3) has the advantages of a high absorption efficiency for low-energy X-rays, a high operating electric field, a low dark current and a high physicochemical stability, and is one of the important candidate materials for direct-conversion X-ray detectors. This paper reviews the progress of X-ray detection characteristics of Ga2O3 and its device research from the perspectives of material, device structure, photoelectric conversion mechanism, and device application. At present, the X-ray detectors using amorphous Ga2O3 thin films, polycrystalline (including microcrystalline and nanocrystalline) Ga2O3 thin films, highly oriented epitaxial single-crystal Ga2O3 thin films, single-crystal Ga2O3 bulks, and single-crystal Ga2O3 microwires have been fabricated and their detection performances have been studied. The device structures employed include metal-semiconductor-metal (MSM), Schottky junction, heterojunction, and vacuum structure. Various photoelectric conversion mechanism, such as photoconductive gain, avalanche gain, and electron bombardment induced photoconductivity effect, have been proposed. In terms of device applications, the applications of Ga2O3 X-ray detectors in X-ray dosimeters, X-ray imaging, and wearable X-ray sensors have been displayed. Based on the above research progress, this paper further looks forward to the future development direction of Ga2O3 based X-ray detectors.
Dong Jingnan, Duo Yiwei, Yang Jiankun, Wang Junxi, Wei Tongbo
DOI:10.37188/CJL.20250128
摘要:Hexagonal boron nitride (h-BN) is a representative wide-bandgap two-dimensional layered material with an atomically complete surface and no dangling bonds and charged impurities, and has excellent mechanical stability, thermal stability and chemical inertness. Because it exhibits extraordinary properties in the fields of optoelectronics, quantum optics and electronics, it has become a low-dimensional substrate material carrier for various application scenarios. In this paper, the basic structure of h-BN and the properties of optoelectal, mechanical, thermal and other materials are systematically introduced, and then the latest preparation methods of h-BN are described, including exfoliation, chemical and physical vapor deposition, and molecular beam epitaxy. Then, the latest research progress of h-BN device applications is introduced from multiple dimensions, such as transfer medium, FET gate dielectric layer, DUV optoelectronic device, single photon source and neutron detection. Finally, based on the research status and key problems of h-BN, some challenges and bottlenecks are analyzed, and the future development direction is proposed.
摘要:To enhance the upper temperature measurement limit and accuracy of phosphor thermometry for two-dimensional surface temperature measurement, this study employed high-temperature solid-state reaction and chemical bonding methods to fabricate Dy³⁺-doped YAG/YAP phosphor coatings with higher temperature sensitivity. Based on the principle that the intensity ratio of characteristic phosphor emission peaks is temperature-sensitive, phosphor intensity ratio versus temperature calibration curves were established. Building upon this, a phosphor thermometry system was developed for mapping surface temperature distributions in high-temperature environments. Comparative temperature measurement experiments were conducted with an infrared thermographic camera. The results demonstrate that this system exhibits excellent performance for 2D temperature distribution measurement within the range of 650–1300 K, with a maximum measurement error of 1.24% and a system uncertainty of 1.60 K. It shows considerable application potential for surface temperature measurement of high-temperature targets such as in supersonic wind tunnels and hot-end components of aero-engines.
关键词:phosphorescent intensity ratio;temperature sensitive phosphorescent coating;non-contact thermometry;surface temperature distribution
Liang Ruiquan, Liu Qian, Hu Chunhua, Zheng Jianzha, Li Yang, Wang Yiwen, Mai Yaohua
DOI:10.37188/CJL.20250149
摘要:Perovskite solar cells (PSCs) have garnered significant attention in the realm of innovative photovoltaic technologies due to their impressive performance. Traditional trial-and-error experimental methods often result in lengthy research cycles to enhance the power conversion efficiency (PCE) of PSCs. We propose a machine learning (ML)-based intelligent optimization strategy to accelerate research cycles in PSC fabrication. By applying various ML algorithms to develop PCE prediction models, the gradient boosting (gradient boosting, GB) model was chosen for shapley additive explanations (SHAP) visualization analysis and experimental validation. The experimental results revealed that the design guided by model predictions and SHAP analysis achieved a PCE of 21.81% for wide bandgap (1.65 eV) PSCs. This study effectively addresses the limitations of conventional trial-and-error approaches and overcomes the challenge of low predictive accuracy in ML applications within the PSC domain. It provides a new perspective and scientific basis for the rapid development of high-PCE PSCs, and also offers a reference for the development of other new solar cell technologies.
关键词:perovskite solar cells;machine learning;SHAP analysis;PCE prediction
YANG Qi, ZENG Ming, ZHOU Wen-qi, DENG Kun, LI Gen, YANG Liu, LI Yue-bin
DOI:10.37188/CJL.20250148
摘要:Vanadium dioxide (VO2), a semiconductor material with a narrow bandgap and reversible metal-insulator transition (MIT) characteristics, exhibits promising potential for near-infrared (NIR) photodetection. In this work, monoclinic VO2 (M1) thin films were successfully synthesized on p-type silicon substrates using DC magnetron sputtering of a metallic vanadium target followed by a post-annealing process. The results reveal that the as-prepared films possess uniform and dense granular morphology and exhibit preferentially (011)-oriented VO2 (M1) phase at room temperature, transitioning to rutile-phase VO2 (R) when heated to 70 °C. Subsequently, a metal-semiconductor-metal (MSM) structured NIR photodetector (Ag/VO2/Ag) was constructed. Under a bias voltage of 1.5 V and 980 nm NIR illumination, the device demonstrates outstanding photoresponse performance at room temperature. When the optical power density is 0.07 mW/cm2, the responsivity and specific detectivity reach peak values of 109.06 mA/W and of 2.33×1010 Jones, respectively, accompanied by rise/decay times of 0.256/0.427 s. Temperature-dependent analysis shows a gradual enhancement in responsivity with increasing temperature between 20–80 °C, primarily attributed to the enhanced carrier concentration induced by the M1→R phase transition of VO2. Furthermore, the device maintains broadband photoresponse across the visible-NIR spectral range (455–1100 nm).
ZHANG Zhen, HU Dezhong, REN Binyan, HE Qian, SHEN Baofa, ZHANG Kaixuan, ZHAO Weijie
DOI:10.37188/CJL.20250144
摘要:Chiral halide perovskites have exceptional optoelectronic properties of halide perovskites and chiral properties of chiral molecule, therefore they show great potential in chiral-optoelectronic, spintronic and quantum photonic applications. However, the chiral and nonlinear optical properties of chiral two-dimensional (2D) and quasi-2D halide perovskites are still not well-understood. In this study, we prepared precursor solutions with varying stoichiometric ratios to fabricate 2D and quasi-2D chiral perovskite thin films of (R-/S-3BrMBA)2(Cs0.5MA0.5)<n>-1Pb<n>I3<n>+1 (<n> = 1, 2, 3) via the solution spin-coating method. Chirality was successfully transferred from chiral organic cations to perovskite sublattices. We further revealed the second harmonic generation (SHG) of quasi-2D chiral halide perovskites for the first time to the best of our knowledge. We found that the SHG efficiency has a significant dependence on excitation wavelength and shows a remarkable exciton resonance phenomenon. Our findings provide new insights in nonlinear optical properties and potential application of chiral halide perovskites.
WANG Haijun, WANG Jin, LV Jun, BI Weihui, YANG Pochuan, WANG Tao, ZHONG Yufei
DOI:10.37188/CJL.20250142
摘要:Perovskite solar cells (PSCs) demonstrate outstanding photoelectric conversion efficiency (PCE), yet their performance remains constrained by surface defects at the perovskite/electron transport layer (ETL) interface, which significantly impede electron transport. This study innovatively introduces a LiF interlayer between perovskite and ETL through vacuum thermal evaporation. Research reveals that F⁻ in LiF chemically interacts with uncoordinated Pb²⁺ defects on the perovskite surface, forming stable Pb-F bonds that effectively passivate surface defects. This strategy enhances the film's surface morphology and substantially improves interfacial electron transport efficiency. Experimental results show that LiF-passivated PSCs achieve a PCE increase from 21.21% to 22.33%, accompanied by significantly reduced hysteresis index(HI). During accelerated aging tests at 60 ℃, LiF-modified devices exhibit exceptional stability, retaining 85% of their initial efficiency after 820 hours of aging. This simple, reliable, and scalable interfacial engineering strategy provides new insights for developing high-efficiency and stable PSCs.
关键词:perovskite solar cells;Vacuum thermal evaporation;Passivation of interfacial defect
CHEN Junlin, WANG Qiang, WANG Chuanlong, HUANG Xiaoxiao, DONG Zhaoshi, WEN Jun
DOI:10.37188/CJL.20250126
摘要:The full-spectrum lighting technology aims to address the deficiencies of existing white light-emitting diodes (LEDs), such as high correlated color temperature and insufficient color rendering index. The development of low-cost, efficient and stable non-rare-earth blue phosphors that can be excited by the near-ultraviolet has been an important research topic. In this study, a series of Sr3B2O6:Bi3+ blue phosphors were successfully synthesized through the high-temperature solid-phase method. The experimental results show that when the optimal doping concentration of Bi³⁺ is 0.02%, this material exhibits blue light emission characteristics under the excitation of near-ultraviolet light at 365 nm. Its emission peak is located at 450 nm, and the full width at half maximum is 69.4 nm. The quantum yield of the blue phosphors is 42.6%, and the emission intensity at 423 K can be maintained at 80.29% at room temperature, showing excellent thermal stability. Based on the encapsulation of commercial green phosphor (Ba,Sr)2SiO4:Eu2+ and nitride red phosphor CaAlSiN3:Eu2+, a full-spectrum white LED device was prepared. Under a driving current of 20 mA, it exhibits low correlated color temperature(CCT = 5684 K) and high color rendering index(Ra = 92.9). The research shows that this blue phosphor has significant application potential in full-spectrum lighting technology and provides a solid material foundation for the development of related technologies.
XIE Jun, ZHANG Wei, XIE Zijing, XU Shenghai, WANG Hong
DOI:10.37188/CJL.20250138
摘要:The low light extraction efficiency of AlGaInP-based red light Micro-LEDs limits the luminescence intensity of the devices. A self-assembled Ni metal nanomask and wet etching technique was proposed to obtain GaP surface texture with high density and high uniformity. The critical angle is increased by surface texture to reduce the total internal reflection effect, thereby effectively improving the efficiency of light extraction. Different surface textures were obtained by using nickel masks of different thicknesses. The results show that at a current density of 20 A/cm2, the luminescent intensity and external quantum efficiency of the Micro-LED wet-etched with a 1 nm thick nickel metal nano-mask are increased by 21.04% and 23.58%, respectively, compared with the Micro-LED without surface texture. Another method for preparing honeycomb cylindrical surface texture using ICP dry etching combined with wet etching was proposed. The GaP layer was wet-etched for different durations after the same ICP etching process. The results show that when the current density is 20 A/cm2, the luminous intensity and external quantum efficiency of Micro-LED etched by ICP and wet etching for 10 seconds *3 times are increased by 81.61% and 48.40%, respectively, compared with the Micro-LED without surface texture.
摘要:Optical imaging in the second near-infrared window (NIR-II, 1000–2000 nm) significantly improves in vivo imaging depth and resolution by reducing tissue scattering and autofluorescence. Over the past decade, the development of diverse NIR-II probes and imaging setups has enabled NIR-II imaging to overcome the penetration depth limitations of conventional optical techniques, achieving cross-scale dynamic observation from macroscopic anatomical structures to microscopic molecular events, thereby providing revolutionary tools for biomedical research. This review systematically summarizes recent advances in the design of NIR-II luminescent probes and their biomedical applications. The optical properties of various NIR-II probes are discussed, with a focus on their innovative applications in anatomical structure imaging, precision tumor diagnosis and therapy, real-time tracking of molecular events in vivo, responsive imaging, microenvironment visualization, and the construction of integrated theranostic platforms. Finally, critical summaries and perspectives on the development and applications of NIR-II luminescent materials are presented, highlighting their potential for broader impacts in fundamental research and clinical translation.
XIE Lei, LI Teng, XU Xinqi, CHEN Xiaofeng, CHEN Qiushui, YANG Huanghao
DOI:10.37188/CJL.20250124
摘要:Liquid scintillators have been widely applied in nuclear radiation detection field due to their advantages including rapid response, high sensitivity, radiation damage resistance, cost-effectiveness, facile preparation, and diverse functions. In recent years, the emergence of perovskite liquid scintillators demonstrating high X/γ-rays stopping power, high photoluminescence quantum yield, and tunable radioluminescence properties, have significantly expanded their applications in radiation detection and imaging. This review systematically summarizes recent progress of perovskite liquid scintillators, encompassing advancements in synthesis methodologies, optical properties tailoring, and elucidation of radioluminescence mechanisms interacted with various ionizing radiation. Furthermore, we comprehensively discuss emerging applications of these novel scintillators in radiation detection, location and imaging, while providing critical perspectives on future research directions in this evolving field.
Chang Jiaying, Qian Yanrong, Zhu Guoqing, Gao Minghong, Li Chunxia
DOI:10.37188/CJL.20250139
摘要:Near-Infrared-IIb (NIR-IIb) fluorescence exhibits exceptional deep-tissue penetration, low scattering characteristics, and a high signal-to-noise ratio. By effectively suppressing tissue autofluorescence and photon scattering, it has achieved unprecedented spatial resolution and signal-to-noise ratio, thereby emerging as a research frontier in precision medical imaging. Rare-earth luminescent nanocrystals with lanthanide elements as core components, serving as unique optical probes, leverage the distinctive 4f electronic transitions to generate narrowband emission through upconversion/downconversion luminescence mechanisms under near-infrared excitation. Their millisecond-scale luminescence lifetimes further establish them as an ideal solution for NIR-IIb imaging. Recent advances in energy-level engineering and surface modification strategies have successfully integrated multifunctional therapeutic capabilities, including photothermal therapy, photodynamic therapy and immunotherapy, establishing integrated theranostics as an innovative paradigm in tumor treatment. This review systematically summarizes groundbreaking progress in NIR-IIb-emitting rare-earth nanocrystals for biomedical imaging and oncotherapy, aiming to inspire innovative research directions for next-generation precision medicine.
WANG Longchao, GAO Shaohua, XIE Shuhao, DANG Jie, LI Yang, ZHU Yizhi, ZHANG Mingjiang
DOI:10.37188/CJL.20250121
摘要:Random fiber lasers have significant application potential in areas such as imaging, sensing, and medical diagnostics. This paper proposes a random fiber laser based on feedback from a liquid crystal core random grating array, by utilizing a random grating array mask and light-induced phase separation technology, a liquid crystal core grating array with randomly distributed gratings was realized within a hollow-core optical fiber, which is integrated into the optical path to provide random feedback for the laser. The threshold of the random fiber laser at room temperature is 49.3 mW. As the pump intensity gradually increases, the number of lasing modes increases, with the lasing modes dynamically distributed over the range of 1529-1532 nm and exhibiting a relatively small range of lasing intensity variations. The temperature variation of the random grating array will affect the lasing characteristics of the random fiber laser. As the temperature rises, the feedback strength of the grating array decreases, resulting in an increased lasing threshold and a decreased lasing intensity. Additionally, the probability of lasing modes around 1530.9 and 1531.3 nm significantly increases. This kind of multi-mode random fiber laser based on liquid crystal core random grating array feedback has great application potential in the fields of sensing, communication and imaging.
DUAN Yijiang, CHEN Chao, SUN Jingjing, ZHANG Jianwei, LIU Zhaohui, CHEN Peng, ZHOU Yinli, WU Hao, ZHANG Zhuo, LIU Tianjiao, ZHANG Dayong, NING Yongqiang, WANG Lijun
DOI:10.37188/CJL.20250114
摘要:The semiconductor gain chip, serving as the active medium of external cavity semiconductor lasers (ECSL), directly determines the core performance of the laser through its characteristics including output power, polarization dependence, and linewidth enhancement factor. To enhance the polarization extinction ratio of semiconductor gain chips and mitigate mode competition-induced noise in lasers, this study investigates the effects of quantum well thickness and quantum well strain on the material gains of transverse electric (TE) and transverse magnetic (TM) modes, while simultaneously exploring the influence of cavity length on the output power and spontaneous emission spectrum of the gain chip. By introducing compressive strain into the InGaAs/AlGaAs quantum wells, the material gain difference between TE and TM modes was significantly enhanced, resulting in an 850 nm-band semiconductor gain chip with pronounced polarization characteristics. The optimized device demonstrates a maximum polarization extinction ratio of 9.58 dB, a broad spontaneous emission spectral bandwidth of 28.72 nm, and a peak output power of 28.53 mW. This work provides an active gain medium with distinctive polarization properties for applications requiring narrow-linewidth linearly polarized lasers in quantum precision measurement, coherent lidar systems, and coherent optical communications.
ZHANG Yijia, FU Xinpeng, RUAN Di, LIU Zhen, FU Xihong, BAI Suping, WANG JI
DOI:10.37188/CJL.20250087
摘要:Solid-state master oscillator power amplifier (MOPA) lasers are devices that combine the master oscillator and power amplifier of solid-state lasers to amplify low-power signals and output high-power lasers. They are widely used in laser processing, precision measurement, medical treatment, and scientific research. Beam quality, as a key indicator of laser output performance, directly determines the effect and accuracy of the laser in these applications. However, due to the thermal effect in solid-state MOPA lasers, the beam quality often deteriorates continuously during the laser output process, leading to performance degradation. Therefore, optimizing beam quality has become a key to improving laser performance and has significant research and practical significance in the design and application of lasers. This paper reviews the research progress of beam quality optimization techniques for solid-state MOPA lasers, focusing on introducing optimization methods such as thermal effect suppression technology, negative lens method, phase conjugation method, deformable mirror method, spherical aberration self-compensation method, gain guiding method, and beam shaping method. By analyzing the principles, experimental progress, and application effects of these technologies, the challenges and innovative achievements in improving beam quality are discussed. In addition, the difficulties in optimizing beam quality under high-power and high-efficiency conditions for solid-state MOPA lasers are pointed out by the article, and possible future research directions and technological breakthroughs are anticipated.
Kong Deqi, Qin Feng, Yang Zhuo, Liu Deming, Liu Lei, Shen Dezhen
DOI:10.37188/CJL.20250076
摘要:This study successfully prepared efficient photocatalytic nanocluster materials by combining rare earth-doped upconversion nanoparticles (NaREF₄) with metal oxides (TiO₂, ZnO). By employing a high-concentration Yb³⁺ doping strategy through shell layer epitaxy, the emission of ultraviolet light was enhanced. Furthermore, a core-shell structure was constructed, utilizing the physical isolation effect of the inert shell layer to effectively suppress the fluorescence quenching phenomenon caused by surface defects in the luminescent centers. Using a water-in-oil microemulsion self-assembly technique, NaREF₄/MO nanoclusters with a hierarchical structure were fabricated. This composite system successfully achieved sensitized excitation of wide bandgap semiconductor oxides in the near-infrared region through an interfacial energy transfer mechanism. Under the irradiation of a xenon lamp, the photocatalytic performance of the nanoclusters was verified by the degradation of methylene blue dye. Experimental results demonstrated that the NaREF₄/MO nanocluster structure exhibited excellent catalytic performance, with precise control over the catalytic effect achieved by adjusting the ratio of NaREF₄ to MO (1:2), resulting in a degradation rate of 100% after 20 minutes of irradiation. This performance was 40% higher than that of pure ZnO nanoparticles under the same conditions for the degradation of methylene blue solution.
关键词:Sodium rare earth fluoride;Wide-bandgap metal oxides;photocatalysis;UCNP Nanoclusters
QIU XianChun, ZHU Meng, HUANG He, ZENG Zimeng, WANG Zhaona
DOI:10.37188/CJL.20250131
摘要:Miniaturized, low-power, and high-performance photoelectric sensor is a key research topic in integrated optoelectronic chips and intelligent sensors. Particularly, pyrophototronic detectors have emerged as a vital research direction in optoelectronic sensing due to their self-powered capability, fast response, high responsivity, and broad bandwidth. Here, the fundamental principles of pyro-phototronic effect are elucidated, followed by an overview of performance optimization strategies and specialized applications of this effect in various junctions-based photodetectors. Subsequently, enhancement of non-uniform polarization field on pyrophototronic effects in PN junctions is demonstrated through enhancement mechanism and constructing methodologies for gradient polarization fields. Based on the engineered gradient polarization, we achieved the PN-junction pyrophototronic detectors with superior performances in responsivity and spectral bandwidth. Finally, we offer insight into the future development of pyrophototronic detectors in design principles, device architectures, and specific applications. The studies on polarization-field-tuned photodetectors offer flexible design paradigms for advancing pyrophototronic sensing, which might significantly accelerate the practical applications of pyrophototronic detectors in smart sensing, communication and ultrafast imaging.